Oven heater combination

ABSTRACT

A closed combustion oven heater combination to be mounted in a room of an enclosed structure, such as a camper, motor home and the like and having an oven enclosure, a closed combustion chamber disposed under the oven enclosure, ducting for bringing intake air into the combustion chamber from outside the room, heat exchanging flue spaces in communication with the combustion chamber for heating the oven, exhaust ducting communication with the heat exchanging flue spaces, and a vent to allow heated air to escape from the oven enclosure. The oven enclosure is thus completely closed from the combustion chamber and the air source so that oven enclosure air which may be circulated into a room of the enclosed structure is independent of the air circulation of the combustion chamber.

United States Patent Skafte 1 June 6, 1972 OVEN HEATER COMBINATION 3,364,912 1/1968 DillS et a1. ..126/21 A [72] Inventor: Stanley F. Skafte, Arcadia, Calif. FOREIGN PATENTS OR PL C Assigne9= Williams Furnace 6 Buena Park, Calif. 214,671 5 1924 Great Britain ..126/85 B [22] Filed: Oct. 1970 Primary ExaininerCharles J. Myhre [21] Appl. No.: 77,449 Attorney-Fowler, Knobbe & Martens Related US. Application Data 57 ABSTRACT Continuation-impart 0f 7 1970, A closed combustion oven heater combination to be mounted abandoned. in a room of an enclosed structure, such as a camper, motor home and the like and having an oven enclosure, a closed [52] 1.1.8. Cl ..l26/85 B, 126/39 R, 126/39 D combustion chamber disposed under the oven enclosure, [51] Int. Cl. ..F24c 3/00 ducting for bringing intake air into the combustion chamber [58] Field of Search ..126/21, 21 A, 39, 39 C, 39 D, f om ou de t e room, eat e c ngin flue spaces in com- 126/8 5 B 299 299 B munication with the combustion chamber for heating the oven, exhaust ducting communication with the heat exchang- 56] References Cited ing flue spaces, and a vent to allow heated air to escape from the oven enclosure. The oven enclosure is thus completely UNITED STATES PATENTS closed from the combustion chamber and the air source so that oven enclosure air which may be circulated into a room of 3'48000O 1 1/1968 et a1 "126/21 A x the enclosed structure is independent of the air circulation of 2,634,718 4/1953 'W1l11ams 126/39 X the combustion chamber 3,485,229 12/1969 Gilliom ..126/21 A 2,647,477 8/1953 Martin ..l26/85 B UX 9 Claims, 8 Drawing Figures PATENTEnJun s 1912 SHEET 2 OF 3 INVENTOR. STA/V15) E SKAIFTE pan 4 5e, K/VOBBE MOE- TEA/5' OVEN HEATER COMBINATION This invention relates to an oven heater combination which is specifically adapted for use in a room of any enclosed structure, such as a camper, motor home and the like. The application is a continuation-impart of an application filed Mar. 4, 1970, Ser. No. 16,282, now abandoned.

I In the usual fuel fired stove having an oven, the products of combustion from the oven are discharged into the room in which they are installed; and in addition, the air for combustion is taken from the room. In campers, motor homes and thelike, the volume of air in the room is limited due to the overall. size of the structure. Unless the space is well ventilated, there is a danger of asphyxiation to persons occupying the room because of combustion products and oxygen starvation. v

In'many cases it isthe practice of users of these vehicles to use the oven as a means of auxiliary heat when not used for cooking. This can be very dangerous to the occupants health.

It is desired to provide an oven heater combination constructed so that the products of combustion are exhausted outside the room and the required air for combustion is drawn from the outside.

The invention, briefly described, comprises a combustion chamber disposed adjacent the bottom of an oven enclosure in such a manner that the intake air for combustion is ducted from an outside source, combustion occurs in the chamber, and the combustion products flow through heat exchanging flue spaces which transmit heat to the oven enclosure. A room air inlet in the oven enclosure allows room air to enter the oven enclosure, and a selectively controllable opening in the oven enclosure allows the heated air to escape from the oven to warm the room in which the oven heater combination is installed. After flowing through the flue spaces, the combustion products are exhausted outside of the room. In other words, the combustion process and exhaust are essentially sealed from the room in which the oven is installed, thus avoiding the problem of asphyxiation and oxygen starvation. In a preferred form of the invention the combustion chamber and flue space are formed and installed as a separate sealed unit, thus simplifying manufacturing problems.

With this basic description of the novel apparatus in mind, the invention may be further understood by reference to the drawings in which FIG. 1 shows a sectional side view of the preferred embodiment of the oven heater combination on the line 11 of FIG.

FIG. 2 shows a sectional front view of the preferred embodiment on the line 22 ofFIG. 1;

FIG. 3 shows an enlarged sectional view of the construction for venting the oven heat shown in FIG. 1;

FIG. 4 shows an enlarged sectional view of an alternate construction for venting the oven heat;

. FIG. 5 shows a sectional side view of an alternate embodiment of the oven heater combination with a lower cooking portion cut away;

FIG. 6 is a cross-sectional view of a preferred embodiment of the invention taken on line 6-6 of FIG. 7;

FIG. 7 is a view partially in cross-section on line 77 of FIG. 6 and a fragmentary view showing the lower left front comer of the interior of the oven enclosure; and

FIG. 8 is a fragmentary view showing the edge of the baffle plate.

Referring now to FIGS. 1 and 2, there is shown an oven heater combination having an outer housing structure 10 comprising a vertical rear wall 12 attached to vertical side walls 14 with a bottom wall 16 and a top wall 18 attached respectively to the bottom and top of the rear wall 12 and the side walls 14. These walls together define an open sided box to which is added a front wall 20 containing openings to allow affixing suitable access doors.

Disposed inwardly at a small distance from and parallel to the-bottom wall 16 is an inner bottom wall 22 which is attached at its outer edges to the respective walls of the outer housing 10. Disposed at a distance from and parallel to the top wall 18 is an inner top wall 24 intersecting with and attached to the front wall 20. Inner top wall 24 intersects with and is attached to an inner rear wall 26 which is spaced from and parallel to the rear wall 12. The inner rear wall 26 terminates at its lower edge at a distance above the inner bottom wall 22 and is rigidly fastened to the rear wall 12 by a plate 34 which closes the space between the rear wall 12 and the inner rear wall 26, the plate being disposed at a distance above the inner rear wall 26 termination. Inner side walls 28 extend parallel to and spaced from the side walls 14 and intersect with and are attached at the extreme edges to the inner rear wall 26, the inner bottom wall 22, the front wall 20, and the inner top wall 24 respectively.

This completes an open sided inner box 30 whose walls are spaced inwardly from the walls of the outer housing 10 except for the front wall 20 which is common to both. In the spaces between the outer housing 10 and the inner box 30 is suitable insulation 32. 7

An oven enclosure 36 is defined within the outer housing 10 as follows. A portion of the inner top wall 24 forms the top panel of the oven enclosure. Vertical side panels 38 spaced inwardly from and parallel to the inner side walls 28 are attached at the extreme top edges of the panels to the inner top wall 24 and at their front edges tothe front wall 20. The panels 38 are further attached to a rear panel 40 which is parallel to and spaced inwardly from the inner rear wall 26. Spaced from and parallel to the inner bottom wall 22 isa bottom panel 42 extending between and attached to the side panels 38 and the front wall 20 as well as intersecting with and being attached to rear panel 40. An oven door 44 is attached by hinges not shown to the front wall 20 in order to complete the oven enclosure 36. Just below the door 44 on the front wall 20 is a slotted opening 46 which allows communication between the air in the surrounding room and the air inside the oven enclosure 36. I

A combustion chamber 48 disposed below the oven enclosure 36 is defined as follows.- The lower portion of the front wall 20 forms the front wall of the chamber 48, the inner bottom wall 22 forms the chamber bottom wall, and the inner side walls 28 form the sides of the chamber. Placed over a suitable opening in the front wall 20 is a door 50 which permits access to the chamber 48. The rear of the chamber 48 is in communication with suitable intake ducts later described. This is accomplished by positioning a baffle 52 spaced from the inner bottom wall 22 and extending between and attached to the inner side walls 28. The front edge of the baffle 52 is spaced from the front wall 20. A vertical rear plate 54 extending between the inner side walls 28 and attached at its upper edge to the panel 42 intersects with and is attachedto the baffle 52 at its rear edge to fonn a rear wall of the combustion chamber. The plate 54 may also be an extension of the rear oven panel 40. A horizontal plate 56 extending between inner side walls 28 is affixed to inner rear wall 26 and oven panel 40 essentially in the plane of the bottom panel 42. A space 58 is formed between plate 54 and the lower portion 59 of inner rear wall 26, its upper limits defined by plate 56.

The combustion chamber 48 is in direct communication with side heat exchanging flue spaces 60 shown in FIG. 2 and is in direct communication with the rear heat exchanging flue space 62, shown in FIG. 1. These flue spaces are formed by the respective walls of the inner box 30 and the panels of the oven enclosure 36.

A burner 64 extends from the front of the chamber 48 to the rear, attached to the lower portion of the front wall 20 and supported at the rear by a leg 66 which is affixed to the bafile 52.

A heat shield 68 is attached to and disposed below the bottom panel 42 and extends between the side panels 38 with the frontto rear center line of the panel spaced from the bottompanel 42. The side edges of the shield slope into engagement with the bottom panel 42, as seen in FIG. 2, the spacing being approximately one-half inch at its maximum distance from the bottom panel 42. As seen from FIG. 1, the shield 68 extends from the front to the back of the combustion chamber 48 to protect the panel 42 from the burner 64.

Suitably placed on the upper surface of the top wall 18, with its vertical walls 70 aligned with the respective walls of the outer housing 10, is a surface burner housing 71. A removable top plate 72 is adapted to accept suitable cooking grates 74. Enclosed in the housing 71 are cooking burners 76 and the valved pipes 78 for feeding the fuel. Additionally, the front panel 80 contains appropriate cutouts for insertion of control knobs 82. 7

As can be seen from FIG. 1, near the rear and at the top of the oven enclosure 36 is an opening 84. As shown in FIG. 3, the opening 84 has a collar 86 to which is attached a hinged cover plate 88. The selection'of a desired position of the cover plate 88 between the open and closed positions shown in FIG. 3 is accomplished by suitably attaching a rod 90 to the cover plate 88, the rod terminating near the front of the housing 71, as shown in FIG. 1, and by providing rod 90 with a series of detent positions not shown.

An alternate way of opening the cover plate 88 is shown in FIG. 4. There, an arm 190 is provided with a forked end 192 to suitably engage a fastening rod 194 attached to the cover plate 88, the arm 190 being pivoted at a point 196 to open or close the cover plate when the arm is moved as shown in FIG. 4 by arrow 198.

With reference to FIG. 1, the opening 84 terminates in a vent housing 100 which provides a direct path of communication between the oven enclosure 36 and the room of the camper, mobile home and the like.

In order to insure the desired operation of the oven heater combination, it must be mounted so as to provide access to outside air. As shown in FIG. 1, this is accomplished by placing the apparatus in proximity of an outer wall 102 which represents the wall of a camper, motor home and the like or other relatively enclosed small structure. A section of the wall 102 is removed, the resulting opening being large enough to accommodate an intake and exhaust housing 103 defining a chamber 104. The chamber 104 is essentially closed on all sides except the louvered outer side 106. The housing 103 is installed in the outer wall 102 so the closed portion faces the rear wall 12 of the oven heater combination. An air intake duct 108 connects the lower portion of the chamber 104 to the rear wall 12 so that the chamber 104 is open to the combustion chamber 48. A second duct 1 attached to the top of the housing 103 and the back wall 12 provides an exhaust-path from the rear flue space 62 to the upper portion of the chamber 104.

Having described the structure and with reference to FIGS. 1 and 2, the apparatus operates in the following manner. Natural convection currents allow outside air to flow in through the lower area of the louvered outer panel 106, through the lower portion of the chamber 104 and into, the intake duct 108. The intake air is drawn by convection into space 112 under the baffle 52 as shown by arrows. In taking this path the intake air has passed air space 58 which forms somewhat of a dead air space or buffer zone between the rear of the combustion chamber 48 and the intake air, minimizing preheating of the intake air. Heated intake air would result in less positive flow into the combustion chamber 48. The baffle 52 insures that the intake air will uniformly flow to near the front of the combustion chamber 48 instead of supplying only the rear portion. Also, the presence of the baffle makes combustion less affected by pressure variations of the outside air.

The burner 64 will have been lit by access to the door 50 which is then shut to close the combustion chamber 48 from the air in the surrounding room. The intake air upon reaching the vicinity of the burner 64 will combust with the fuel. The heat shield 68 acts as a conductor to transfer some of the combustion heat to the bottom oven panel 42 as well as protecting the bottom panel 42 from the concentrated heat of the burner 64.

Because the combustion chamber 48 is in communication with the flue spaces 60 and 62, the hot combustion products will flow by convection directly upward and into the side flue spaces 60, but since vertical plate 54 cooperates with plate 56 to close off direct access to the rear flue space 62, the combustion products must first flow into spaces 60 before reaching space 62. This increases heating of the side walls and results in more uniform heating of the oven enclosure 36.

The hot combustion products flowing in close proximity to the side oven panels 38 and the rear oven panel 40 conduct some of their heat through the panels to heat the air inside the oven enclosure 36. The combustion products continue to rise due to their warm temperature and are exhausted through the duct which is in direct communication with rear flue space 62. Thus, it can be seen that the combustion products are exhausted to the outside and do not enter the room of the camper, motor home and the like, the intake air also coming in from the outside.

During the period that intake, combustion, and exhaust are taking place, the oven enclosure 36 may be used for either heating or cooking. To cook, the opening 84 is closed by the cover plate 88 and access to the oven enclosure is through the door 44. For heating, the air that is initially in the oven enclosure will exit through the opening 84 when the cover plate 88 is opened. This exposes a portion of the oven enclosure 36 to the vent housing 100 as shown in FIGS. 1, 3, and 4. Since the vent housing 100 is open to the surrounding room, the heated air escapes into the room. Slotted opening 46 at the bottom of the door 44 allows room air to enter the oven enclosure 36 aiding in the heating of the room by improving circulation through the oven enclosure 36.

An alternate embodiment of the oven heater combination is shown in FIG. 5 as an eye level oven. Here the surface burner housing not shown would be at waist level. The operation of this embodiment is the same as described above except that an opening 184 in the rear, top of an oven enclosure 185 leads directly to a vent housing 200 which is bounded by an outer top wall 202, an inner top wall 204, and side walls not shown. This arrangement directs the heated air through a louver 206 covering the front of the vent housing 200. A hinged door 208 with a plurality of detent positions not shown, allows controlling the flow of heated air into a room of the camper, motor home and the like.

EMBODIMENT OF FIGS. 6-8

Referring now to FIGS. 6-8, there is shown a preferred form of an oven heater combination 310 including an outer insulated box-like oven enclosure 336 comprising a vertical rear wall 312 attached to a pair of vertical side walls 314, a bottom wall 316, a top wall 318 and a front door 344. As will be seen from the drawings, the enclosure walls are double panel construction with insulation therebetween.

Positioned within the lower and back portion of the oven enclosure 336 is a separate sealed unit 338 made of sheet metal construction. This unit has a lower, flat, horizontally oriented box-like section 340 which defines a combustion chamber 342 and a rear vertically oriented box-like riser 344 which forms a flue space 346 for exhausting the combustion products. More specifically, the combined unit 338 includes a bottom wall 348 which extends parallel to the bottom enclosure wall 316, a short front wall 349, a back wall 350, a pair of side walls 351 which include a front short portion forming walls of the combustion chamber section 340 and the taller rear portions which form side walls of the riser 346, a horizontal wall 352 which forms the top of the combustion chamber section 340, a vertical wall 353 which forms the front of the riser 344, and a horizontal wall 354 which forms the top of the riser 346. As can be seen from FIG. 6, the combustion chamber section 340 of the unit 338 is spaced from the bottom enclosure wall 316 so that an air space or passage 358 is formed beneath the unit. A plurality of legs 356 rest on the bottom enclosure wall 316 to support the unit. Also, referring to FIG. 7, it may be seen that the section 340 extends nearly across the width of the oven enclosure but is spaced from the side walls 314 to form a pair of side spaces or passages 360.

Within the section 340 of the unit 338 is positioned a baffle plate 362 which extends horizontally in the combustion chamber parallel to the walls 348 and 352 to divide the combustion chamber 342 into a lower portion 342a and an upper portion 342b. The rear of the baffle plate 362 is attached to the rear vertical wall 350, and the forward edge of the plate is spaced from the front wall 349. The plate 362 extends completely across the combustion chamber and may be attached by suitable means not shown to the side walls 351. Referring to FIG. 8, the side edges of the baffle plate 362 have a series of notches 363 which permit gasses to pass from the lower portion 342a of the combustion chamber to the upper portion 342b.

Attached to the 'rear of the oven enclosure wall 312 is a rectangular collar 370 which slidably fits with a mating combustion air intake and exhaust housing 372 which extends through a wall 374 of the room in which the oven heater is positioned. The outer end of the housing 372 is closed by a vent cover 373 having an air inlet 375 and an air outlet 377.

As may be seen in FIG. 6, attached to the lower rear portion of the back wall 350 of the unit 338 is a rectangular collar 364,

which fits within a mating opening in the rear oven housing wall 312. Within the collar 364 extending below the rear of the baffle plate 362 towards the bottom wall 348 is a smaller opening 366.

A burner 368 extends within the lower portion 342a of the combustion chamber, with the rear of the burner extending through the opening 366 into the collar 364. The burner is, of course, to be connected to a suitable fuel supply (not shown). The fuel connections maybe conveniently mounted within the collar 370 and access for lighting the burner may be had to the rear of the burner through the vent cover 373. Also, the burner may be conveniently removed through the rear opening 366.

Attached to the rear upper wall 350 of the vertical 344 is an exhaust duct 376 which slidably connects to a continuation duct 378 extending to the outlet 377 in the rear cover 373.

Within the interior of the oven enclosure 336 a bottom horizontal panel 384 covers the top wall 352 of the combustion chamber section 340 of the unit 338. This panel 384 forms a suitably finished surface for receiving items to be heated in the oven. A pair of vertically short side flanges 384a are formed on each side of the panel 384. A vertically short front panel 386 given two bends for strength, extends downwardly from the front of the panel 384 and is supported at its cornersby legs 384a resting on the bottom enclosure wall 316, as may be seen from the fragmentary view in the lower left corner of FIG. 7. The lower central portion of this front panel 386 is spaced from the bottom wall 316 to define an air inlet 387, as seen in FIG. 6.

The forward end of the bottom wall 316 is spaced from-the lower edge of the front door 344 to define a room air inlet slot 388. A room air outlet slot 390 is'formed in the rear portion of the top oven wall 318. This room air outlet is connected through a suitable duct 392 to the exterior of the oven heater combination 310 in a manner similar to that shown in FIG. 1. The outlet 390 is controlled by a cover 394 by suitable means such as that shown in FIG. 1. An air outlet and cover arrangement comparable to that shown in FIG. 5 could be used instead.

A rear oven panel 396 covers the riser 344 of the unit 338,.

and may be attached by suitable means to the oven enclosure walls. This panel merely conceals the riser 344 and provides a surface more suitable adjacent to the food items to be placed in the oven.

From the foregoing it will be apparent that in operation of the oven heater combination shown in FIGS. 6-8, combustion air is drawn in through the inlet 375 and through the opening 366 into the lower portion 342a of the combustion chamber 342 wherein the burner 368 is positioned. As explained, the incoming air cannot travel directly into the riser 344 because of the presence of the baffle plate 362. Instead, the combustion gases must spread outwardly to travel through the notched spaces 363 adjacent the edges of the baffle plate and forwardly to travel around the front edge of the baffle plate to enter the upper portion 342b of the combustion chamber. This arrangement insures that the hot combustion gases flow in contact with the upper wall 352 of the combustion chamber which in turn is in conductive contact with the oven lower panel 384. Also, the baffle plate 362 spreads the heat so that the heat of the burner is not applied directly to the wall 352 or the lower oven panel 384.

The combustion gas is directed rearwardly in the upper portion 342b to enter the vertical flue space 346 and is exhausted through the ducts 376 and 378 to the outlet 377 in the rear cover 373. Since the riser 344 is in direct contact with the rear panel 396, additional heat transfer is obtained as the combustion products are exhausting.

If the oven is to be used as a heater, the vent cover 394 is open which permits room air to flow through the oven. The room air enters through the inlet 388 adjacent the bottom of the door, passes primarily through the inlet 387 beneath the panel 386 in that the forward edge of the panel 384 is in close proximity to the door 344. From there the air is directed into the passage 358 beneath the combustion chamber 342, through the passages 360 around the sides of the unit 340, and then upwardly through the oven chamber 336 and out the outlet 390. Thus, it can be seen that the room air is directed in good heat exchange relationship with the combustion chamber section 340.

A main advantage of the arrangement of FIGS. 6-8 is that the unit 338 may be separately fabricated and sealed before being installed into the oven. Also, if the unit ever has to be repaired or replaced, it can be separately removed. Another advantage as previously referred to is that the burner 368 may be lit from the rear of the oven and access to the fuel connections may be made at this point. This is advantageous in campers and similar structures where space within the room or within the camper is limited and the exterior cover 373 is usually at a convenient height. 7

If the oven heater combination is to be operated solely as an oven, the vent 394 is, of course, closed with the result that very little room air circulates in and out of the oven.

What is claimed is:

1. Apparatus for heating and cooking which is particularly adapted for installation in a room of an enclosed structure such as a camper, motor home or the like, comprising:

a. an insulated oven enclosure;

b. a unit positioned in the enclosure and forming a combustion chamber and flue space for exhausting the combustion products, said unit being sealed from the oven enclosure and being separately removable from the enclosure as a unit;

c. intake means for introducing air into the combustion chamber from outside of said room;

d. means for connecting the flue space to the exterior of the room;

e. means for ducting room air in heat exchange relation to the sealed unit and through said oven enclosure to heat the room.

2. The apparatus of claim 1 wherein the section of the unit forming the combustion chamber is in the lower portion of the oven enclosure, and said ducting means includes a lower passage beneath the combustion chamber, side passages along the sides of the combustion chamber in communication with said lower passage, an air inlet in the enclosure leading to the lower passage for introducing the room air, and an air outlet in the top of the oven enclosure for venting the heated air into the room.

3. The apparatus of claim 2 wherein said room air inlet is formed by the bottom of the door and the forward edge of the bottom wall of the oven enclosure and the air outlet is in the rear portion of the top wall of the oven enclosure.

4. The apparatus of claim 1 wherein the unit includes a boxlike section forming the combustion chamber positioned in the lower portion of the oven enclosure spaced from the bottom and side walls of the enclosure, and a vertical box-like section forming the flue space being attached to the rear of the combustion chamber section and extending upwardly adjacent the back wall of the oven enclosure.

5. The apparatus of claim 4 including a bafile plate extending between the side walls of the combustion chamber and spaced from the top and bottom walls of the chamber to define upper and lower portions, the rear wall of the baffle plate being attached to the rear of said unit above the inlet for outside air, and portions of the front and side edges of the baffle plate being respectively spaced from the front and side walls of the combustion chamber, the rear part of the upper portion of the combustion chamber being open to the vertical section of said unit which defines the flue space and the apparatus further including a burner located in said lower portion of the combustion chamber.

6. The apparatus of claim 5 wherein said combustion air inlet in the back wallof the housing is sufficiently large to permit the burner to be inserted therethrough to be installed in the combustion chamber.

7. An oven-heater combination which is particularly adapted for installation in a room of a camper, motor home and the like, comprising:

a. an oven enclosure having a box-like shape formed by a bottom wall, a back wall, a pair of side walls, a top wall and a front wall having a door therein;

b. means defining a combustion chamber in the bottom of the enclosure including a bottom wall spaced from the enclosure bottom wall, vertically short side walls spaced from the enclosure side walls, a front wall spaced from the enclosure front wall, a back wall adjacent the enclosure back wall and a top wall parallel to the chamber bottom wall, the combustion chamber being sealed from the enclosure and being separately removable from the enclosure as a unit;

0. an air inlet extending through the oven enclosure back wall and through a wall of said room and opening into the back wall of the chamber for ducting outside air into the combustion chamber;

d. means defining a riser in communication with the rear of the combustion chamber defining a flue space for receiving combustion products including a vertical rear wall forming an extension of the rear wall of the combustion chamber and a vertical front wall extending upwardly from the rear of the top wall of the chamber, side walls forming extensions of the chamber side walls and an upper wall near the upper wall of the enclosure;

e. an exhaust outlet connected to the upper portion of the rear wall of the riser extending through the oven enclosure and a wall of said room for ducting combustion products from the riser to the outside air; and

f. means for ducting room air through the oven enclosure adjacent the chamber walls and the riser walls to heat the room.

8. The combination of claim 7 including a horizontal panel in contact with the upper wall of the combustion chamber to support items in the oven, the side edges of the panel being spaced from the side walls of the enclosure; and a vertical panel in contact with the front wall of the riser and extending upwardly from the rear of the horizontal panel.

9. The combination of claim 7 including a baffle plate extending horizontally in the combustion chamber spaced from the top and bottom walls of the chamber, and a burner positioned beneath the bafile plate, the rear of the plate being connected to the rear wall of the chamber above the outside air inlet and the front of the baffle plate being spaced from the front wall of the chamber so that incoming air is directed forwardly beneath the baffle and combustion products are directed above the baffle and then rearwardly to the riser. 

1. Apparatus for heating and cooking which is particularly adapted for installation in a room of an enclosed structure such as a camper, motor home or the like, comprising: a. an insulated oven enclosure; b. a unit positioned in the enclosure and forming a combustion chamber and flue space for exhausting the combustion products, said unit being sealed from the oven enclosure and being separately removable from the enclosure as a unit; c. intake means for introducing air into the combustion chamber from outside of said room; d. means for connecting the flue space to the exterior of the room; e. means for ducting room air in heat exchange relation to the sealed unit and through said oven enclosure to heat the room.
 2. The apparatus of claim 1 wherein the section of the unit forming the combustion chamber is in the lower portion of the oven enclosure, and said ducting means includes a lower passage beneath the combustion chamber, side passages along the sides of the combustion chamber in communication with said lower passage, an air inlet in the enclosure leading to the lower passage for introducing the room air, and an air outlet in the top of the oven enclosure for venting the heated air into the room.
 3. The apparatus of claim 2 wherein said room air inlet is formed by the bottom of the door and the forward edge of the bottom wall of the oven enclosure and the air outlet is in the rear portion of the top wall of the oven enclosure.
 4. The apparatus of claim 1 wherein the unit includes a box-like section forming the combustion chamber positioned in the lower portion of the oven enclosure spaced from the bottom and side walls of the enclosure, and a vertical box-like section forming the flue space being attached to the rear of the combustion chamber section and extending upwardly adjacent the back wall of the oven enclosure.
 5. The apparatus of claim 4 including a baffle plate extending between the side walls of the combustion chamber and spaced from the top and bottom walls of the chamber to define upper and lower portions, the rear wall of the baffle plate being attached to the rear of said unit above the inlet for outside air, and portions of the front and side edges of the baffle plate being respectively spaced from the front and side walls of the combustion chamber, the rear part of the upper portion of the combustion chamber being open to the vertical section of said unit which defines the flue space and the apparatus further including a burner located in said lower portion of the combustion chamber.
 6. The apparatus of claim 5 wherein said combustion air inlet in the back wall of the housing is sufficiently large to permit the burner to be inserted therethrough to be installed in the combustion chamber.
 7. An oven-heater combination which is particularly adapted for installation in a room of a camper, motor home and the like, comprising: a. an oven enclosure having a box-like shape formed by a bottom wall, a back wall, a pair of side walls, a top wall and a front wall having a door therein; b. means defining a combustion chamber in the bottom of the enclosure including a bottom wall spaced from the enclosure bottom wall, vertically short side walls spaced from the enclosure side walls, a front wall spaced from the enclosure front wall, a back wall adjacent the enclosure baCk wall and a top wall parallel to the chamber bottom wall, the combustion chamber being sealed from the enclosure and being separately removable from the enclosure as a unit; c. an air inlet extending through the oven enclosure back wall and through a wall of said room and opening into the back wall of the chamber for ducting outside air into the combustion chamber; d. means defining a riser in communication with the rear of the combustion chamber defining a flue space for receiving combustion products including a vertical rear wall forming an extension of the rear wall of the combustion chamber and a vertical front wall extending upwardly from the rear of the top wall of the chamber, side walls forming extensions of the chamber side walls and an upper wall near the upper wall of the enclosure; e. an exhaust outlet connected to the upper portion of the rear wall of the riser extending through the oven enclosure and a wall of said room for ducting combustion products from the riser to the outside air; and f. means for ducting room air through the oven enclosure adjacent the chamber walls and the riser walls to heat the room.
 8. The combination of claim 7 including a horizontal panel in contact with the upper wall of the combustion chamber to support items in the oven, the side edges of the panel being spaced from the side walls of the enclosure; and a vertical panel in contact with the front wall of the riser and extending upwardly from the rear of the horizontal panel.
 9. The combination of claim 7 including a baffle plate extending horizontally in the combustion chamber spaced from the top and bottom walls of the chamber, and a burner positioned beneath the baffle plate, the rear of the plate being connected to the rear wall of the chamber above the outside air inlet and the front of the baffle plate being spaced from the front wall of the chamber so that incoming air is directed forwardly beneath the baffle and combustion products are directed above the baffle and then rearwardly to the riser. 